Phosphate salt bowel preparation regimens alter perioperative acid-base and electrolyte balance

  • Tiberiu Ezri
  • Emma Lerner
  • Michael Muggia-Sullam
  • Benjamin Medalion
  • Alexander Tzivian
  • Abraham Cherniak
  • Peter Szmuk
  • Mordechai Shimonov



Hyperphosphatemic acidosis and severe electrolyte disturbances caused by phosphate salts (PO) used for mechanical bowel preparation have been described in occasional case reports prior to bowel resection surgery. We hypothesized that PO used preoperatively for bowel preparation may cause more pronounced acid base and electrolyte changes than polyethylene glycol (PG).


Forty American Society of Anesthesiologists physical status II–III patients were randomly allocated to receive either PO or PG for bowel preparation before intra-abdominal surgery (bowel resection or other major elective intra-abdominal surgeries). Measurements of pH, base deficit, blood gases, lactate, hemoglobin, calcium, magnesium, potassium and phosphorus were undertaken before the laxative administration, intraoperatively, and postoperatively.


Preoperative demographic, hemodynamic and laboratory data were similar in the two groups. Intraoperative calcium (8.4 [0.6] vs 9 [0.5] mg·dL-1) and pH (7.35 [0.04] vs 7.41 [0.03]) were lower, while lactate (1.3 [0.4] vs 0.9 [0.3] mmol·L-1) was higher with PO. Postoperative calcium, magnesium and potassium were lower (8 [0.5] vs 8.9 [0.2] mg·dL-1, 1.68 [0.3] vs 1.8 [0.4] and 3.5 [0.36] vs 3.7 [0.33] mEq·L-1 respectively) while phosphorus (4.1 [0.3] vs 3.3 [0.2] mEq·L-1) was higher with PO. A higher percentage of abnormal values for calcium, potassium, phosphorus and base deficit (66% vs 33%, 25% vs 10%, 19% vs 2% and 28.3% vs 5% respectively) were observed with PO.


Calcium and magnesium changes were more pronounced in patients who received PO for bowel preparation.



Ľacidose hyperphosphatémique et des troubles sévères des électrolytes causés par les sels phosphatés (PO) utilisés pour la préparation intestinale mécanique ont été décrits à ľoccasion dans des présentations de cas avant la résection de ľintestin. Nous avons supposé que les PO utilisés avant ľopération pour la préparation intestinale pouvaient causer plus de changements acide base et électrolytiques que le polyéthylèneglycol (PG).


Quarante patients ďétat physique ASA II–III ont reçu au hasard soit des PO, soit du PG pour la préparation de ľintestin à la chirurgie intra-abdominale comme la résection de ľintestin ou ďautres opérations majeures réglées. Les mesures du pH, du déficit basique, des gaz sanguins, du lactate, de ľhémoglobine, du calcium, du magnésium, du potassium et du phosphore ont été faites avant ľadministration du laxatif, pendant et après ľopération.


Les données démographiques, hémodynamiques et de laboratoire étaient similaires dans les deux groupes. Le calcium (8,4 [0,6] vs 9 [0,5] mg·dL-1) et le pH (7,35 [0,04] vs 7,41 [0,03]) peropératoires étaient plus bas, mais le lactate (1,3 [0,4] vs 0,9 [0,3] mmol·L-1) était plus élevé avec le PO. Le calcium, le magnésium et le potassium postopératoires ont été plus bas (8 [0,5] vs 8,9 [0,2] mg·dL-1, 1,68 [0,3] vs 1,8 [0,4] et 3,5 [0,36] vs 3,7 [0,33] mEq·L-1) tandis que le phosphore (4,1 [0,3] vs 3,3 [0,2] mEq·L-1) a été plus élevé avec le PO. Un plus fort pourcentage de valeurs anormales pour le calcium, le potassium, le phosphore et le déficit basique (66 % vs 33 %, 25 % vs 10 %, 19 % vs 2 % et 28,3 % vs 5 %) a été observé avec le PO.


Les changements notés pour le calcium et le magnésium étaient plus prononcés chez les patients qui ont reçu des PO pour une préparation intestinale.


Bowel Preparation Polyethylene Glycol Polyethylene Glycol Hyperphosphatemia Mechanical Bowel Preparation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

[Les préparations intestinales aux sels phosphatés modifient ľéquilibre périopératoire acide-base et électrolytique]


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© Canadian Anesthesiologists 2006

Authors and Affiliations

  • Tiberiu Ezri
    • 1
    • 8
  • Emma Lerner
    • 2
  • Michael Muggia-Sullam
    • 3
  • Benjamin Medalion
    • 4
  • Alexander Tzivian
  • Abraham Cherniak
    • 5
  • Peter Szmuk
    • 6
  • Mordechai Shimonov
    • 7
  1. 1.Departments of AnesthesiaThe University of Texas Medical School at HoustonHoustonUSA
  2. 2.Department of Internal Medicine “B”The University of Texas Medical School at Houston
  3. 3.Department of Surgery “B”The University of Texas Medical School at Houston
  4. 4.Department of Cardiothoracic SurgeryThe University of Texas Medical School at Houston
  5. 5.Department of Urology, Surgery “A”The University of Texas Medical School at Houston
  6. 6.Department of AnesthesiologyThe University of Texas Medical School at Houston
  7. 7.Department of Surgery “A”Wolfson Medical CenterHolon
  8. 8.Department of Outcomes Research InstituteUniversity of LouisvilleKentuckyUSA

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